21001001321 has 8 divisors (see below), whose sum is σ = 22417675200. Its totient is φ = 19615463280.

The previous prime is 21001001303. The next prime is 21001001389. The reversal of 21001001321 is 12310010012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21001001321 - 2⁶ = 21001001257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001009321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7782566 + ... + 7785263.

It is an arithmetic number, because the mean of its divisors is an integer number (2802209400).

Almost surely, 2^21001001321 is an apocalyptic number.

It is an amenable number.

21001001321 is a deficient number, since it is larger than the sum of its proper divisors (1416673879).

21001001321 is a wasteful number, since it uses less digits than its factorization.

21001001321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15567919.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21001001321 its reverse (12310010012), we get a palindrome (33311011333).

The spelling of 21001001321 in words is "twenty-one billion, one million, one thousand, three hundred twenty-one".